The present invention relates to a kit of removable adapters for converting conventional tire changing machines into tire changing machines for special run-flat tires.
Special tires have long been studied and are currently being manufactured and marketed. Their structure allows, in case of puncture or damage, to avoid their complete deflation despite the lack of internal pressure, accordingly allowing the vehicle to continue to travel without having to replace the damaged tire and thus eliminating the severe consequences of such situations suffered with conventional tires.
The particular structure of these tires, of the tubeless type, entails fitting and rigidly coupling, between the bead seat of the wheel rim and the very tire, a ring of adequate thickness made of an elastomer which, in case of sudden deflation of the tire and consequent reduction of the inflation pressure to zero, continues to bear the weight of the vehicle and allows to continue the regular rolling of the wheel, avoiding any sudden swerving of the vehicle and damages to the tire.
One particularity of these tires is the fact that the inside and outside diameters are different from each other, the former being larger than the latter.
Moreover, the so-called bead has a profile with a particular cross-section and is internally reinforced with an annular steel cable in order to maintain the grip against the edges of the wheel rim.
This in practice makes impossible to use, in order to remove and fit the tires to the wheel rim, the conventional machines that are currently manufactured. Accordingly, due to their limited diffusion owing to the fact that such tires have been marketed only recently, these operations are performed only by hand, by using levers which, during removal, are forcibly inserted between the edge of the wheel rim and the bead of the tire in order to extract it from its seat or to insert it therein during mounting. Heavy hammers are used with which the beads of the tires are struck with rough accuracy in order to force them to pass over the flanges of the tire rims so as to achieve their correct placement and thus complete their mounting.
This operating method is very difficult for operators and is slow and dangerous for the integrity of the wheel rims, since the levers that are employed rest on the edges of the wheel rims in order to be able to apply force in the maneuver for lifting the beads, and the blows inflicted with the hammers sometimes strike the wheel rim instead of the tire.